Comparison of Four Diagnostic Methods for Locating MB2 Canals in Permanent Maxillary First Molars

Context: Failure to locate and treat all root canals is a major cause of endodontic treatment failure. Various diagnostic methods are used to locate second mesiobuccal canal (MB2) canals, including direct visual inspection, loupe magnification, operative microscope, and cone-beam computed tomography (CBCT).

Aims: This study compared the efficacy of four diagnostic methods for locating MB2 canals in extracted human permanent maxillary first molars: direct visual inspection, loupe magnification, operative microscope and CBCT.

Settings and Design: Cross-sectional study.

Methods and Materials: CBCT images of forty extracted human permanent maxillary first molars were obtained. Access cavities were prepared on the teeth and the floor of the pulp chamber was refined. The other 3 analyses (direct visual inspection, loupe with 2.5× magnification and 16× magnification microscope) were carried out.

Statistical Analysis Used: Cohen’s kappa and Cochran’s Q test were employed. A pair-wise comparison using McNemar test was done.

Results: CBCT was the most accurate method for detecting MB2 canals, with a sensitivity of 67.5%. The operative microscope and loupe magnification were also effective, with sensitivities of 62.5% and 52.5%, respectively. Direct visual inspection was the least accurate method, with a sensitivity of only 25%.

Conclusions: These findings suggest that CBCT is the most accurate diagnostic method for locating MB2 canals. However, the operative microscope and loupe magnification are also effective options, especially in cases where CBCT is not available.

Clinical Relevance: Choosing the most accurate diagnostic tool and knowing where to look for the extra mesiobuccal canal is the key to endodontic treatment success.